fix dlg_custom: show it on same monitor as mainform
fix dlg_custom: show it on same monitor as mainform

Alexey-T/CudaText,Alexey-T/CudaText,vhanla/CudaText,vhanla/CudaText,vhanla/CudaText,vhanla/CudaText,vhanla/CudaText,Alexey-T/CudaText,Alexey-T/CudaText,Alexey-T/CudaText,vhanla/CudaText,Alexey-T/CudaText,vhanla/CudaText,vhanla/CudaText,vhanla/CudaText,Alexey-T/CudaText,vhanla/CudaText,Alexey-T/CudaText